Detergent compositions in tablet form

ABSTRACT

A tabletted detergent composition comprises from 45% to 80% by weight of a builder system which is not fully hydrated and from 5% to 30% total water content, wherein the total water content comprises water derived from the builder system, optional ingredients and from added water, wherein the ratio of the total water content to added water content is from 100:1 to 5:4. The tablet exhibits improved hardness and strength.

FIELD OF THE INVENTION

The present invention relates to detergent compositions in tablet formhaving an improved hardness profile.

BACKGROUND OF THE INVENTION

The traditional form of detergent compositions for use in automaticdishwashing or laundry machines is granular or particulate. Suchcompositions are measured and dosed by the consumer and placed in thedispenser of the machine which is located in the door in the case ofdishwashing machines or the dispensing tray of an automatic laundrywashing machine.

In order to simplify the dosing of detergents for automatic washingmachines however, many of the automatic washing detergent compositionsare now provided in the form of non particulate solids such as bars ortablets or briquettes. This provides a number of advantages to both theconsumer and manufacturer. Firstly, such tablets prevent spillage of thedetergent composition. Secondly, the tablets eliminate the need for theconsumer to estimate the dosage of detergent composition required andensure that the correct dosage of detergent composition per wash is usedby the consumer. Thirdly, the use of tablets minimises the contact bythe consumer with the composition.

However, there are a number of problems associated with the use oftablets. In order to provide optimum performance benefits the tabletsrequire a certain dissolution profile during the programme cycle of themachine.

In addition, it is also highly desirable that the tablets possess acertain degree of hardness or tablet strength. In particular the tabletsshould be sufficiently hard to meet safety requirements. Tabletteddetergent compositions are typically highly alkaline and thus oralconsumption must be avoided. However, tablets often appear attractive tochildren, who may attempt to consume them.

Furthermore, it is also desirable that the tablets should be hard enoughso that they preferably do not deteriorate, lose their structure ordecompose upon packing, transport or storage.

Background Art

Detergent tablets and methods of their preparation are known in the art.For example WO 94/23011 discloses stable, bifunctional phosphate-,metasilicate- and polymer free, low alkaline cleaning agent tablet fordishwashing machines. The composition may comprise from 1-60% anhydroussodium carbonate, 0-60% sodium disilicate and 3-10% water.

WO 93/00419 discloses a process for producing phosphate and metasilicatefree, low alkaline cleaning agent tablets for machine dishwashing. Thetablets consist of solid alkali salts of at least one polymer of acrylicacid and builders including anhydrous sodium carbonate. The tablets maycomprise anhydrous sodium disilicate. The carbonate undergoes mixingalone or together with other builders and the polymer and with from5-40% water to result in the partial hydration of the carbonate. Theremaining components are then added and compressed into tablet form.

WO 91/15568 discloses stable, phosphate free detergent tablets for usein dishwashing machines containing anhydrous meta silicate, nonionics,builders, bleach, 35-60% acrylic polymers, 25-50% anhydrous carbonate,4-20% anhydrous sodium sulphate and 1-7% water. The tablets are preparedby compression such that they have a flexural strength of at least 120N.

EPO 481 792 discloses detergent compositions in tablet form comprising apersalt, bleach activator and 5-80% detergent builders, polymers(0.5-15%), alkali metal silicates (0.1%-10%), carbonate and sulphate(not disclosed as anhydrous). Water is not disclosed in the descriptionbut the exemplified tablet composition comprises 13.5-16.5% moisture inaddition to carbonate, alkaline silicate and polymer. The tablets areprepared by compression of the premixed composition.

EPO 170 791 discloses a process for making a washing composition intablet form. The process consists of granulating bleach activator,nonionic surfactants, quaternary ammonium compounds, fatty aminederivatives and aminopropanionic acid derivatives with tabletting aidsand spraying the granulate with a liquid builder and drying to a watercontent of at most 6% and compressing into tablets.

All of the identified prior art documents disclose means of increasingtablet hardness using compression of the granular detergent compositionfollowing pretreatment of the granular composition ingredients. It isthus an aim of the present invention to provide a tabletted detergentcomposition having increased strength without substantially increasingthe compression force.

It is a further aim of the present invention to provide a tablet havingincreased strength and hardness with minimal adaptation of thecompression manufacturing process, particularly with respect to thetooling required for compression of the detergent composition intotablets.

It is a further aim of the present invention to provide a tabletteddetergent composition having the desired dissolution profile.

SUMMARY OF THE INVENTION

The present invention is a carbonate free tabletted detergentcomposition comprising from 45% to 80% of a hydratable builder system,wherein said builder is not fully hydrated and

from 5% to 30% total water content, wherein said total water contentcomprises water derived from said builder system, optional ingredientsand from added water, wherein the ratio of said total water content toadded water content is from 100:1 to 5:4.

All amounts, weights, ratios and percentages are as a % weight of thedetergent composition unless otherwise stated.

DETAILED DESCRIPTION OF THE INVENTION

Thus, according to the present invention the detergent composition is ina tabletted form. As used herein the term tabletted refers to anon-particulate solid, which may be a bar, briquette, cake or tablet.The tabletted detergent composition of the present invention is acarbonate free composition comprising as essential ingredients a nonfully hydrated builder system and water.

Builder System

The carbonate free tabletted detergent composition of the presentinvention comprises as an essential component from 45% to 80%,preferably from 65% to 75% of a detergency builder system. Said builderis not fully hydrated and is preferably less than 50% hydrated, morepreferably less than 30% hydrated, most preferably less than 28%hydrated. As used herein the term fully hydrated builder refers tobuilders in which all the vacant co-ordination sites are occupied bywater molecules. Suitable builders for use herein are described hereinbelow. The builder may comprise essentially of only one buildercomponent or a number of builder components. The degree of hydration ofeach of said components is independent of one another such that theoverall hydration of the builder is the mean value of all of the buildercomponents present in the detergent composition.

According to the present invention suitable builders for use in thepresent invention include inorganic or P-containing detergent buildersincluding the alkali metal, ammonium and alkanolammonium salts ofpolyphosphates (exemplified by the tripolyphosphates, pyrophosphates,and glassy polymeric meta-phosphates), phosphonates, phytic acid,silicates, aluminosilicates and builder/fillers such as sulphates.However, non-phosphate builders are required in some locales.Importantly, the compositions herein function surprisingly well even inthe presence of the so-called "weak" builders (as compared withphosphates) such as citrate, or in the so-called "underbuilt" situationthat may occur with zeolite or layered silicate builders.

Examples of silicate builders are the alkali metal silicates,particularly those having a SiO₂ :Na₂ O ratio in the range 1.6:1 to3.2:1 and layered silicates, such as the layered sodium silicatesdescribed in U.S. Pat. No. 4,664,839, issued May 12, 1987 to H. P.Rieck. NaSKS-6 is the trademark for a crystalline layered silicatemarketed by Hoechst (commonly abbreviated herein as "SKS-6"). Unlikezeolite builders, the Na SKS-6 silicate builder does not containaluminium. NaSKS-6 has the delta-Na₂ SiO₅ morphology form of layeredsilicate. It can be prepared by methods such as those described inGerman DE-A-3,417,649 and DE-A-3,742,043. SKS-6 is a highly preferredlayered silicate for use herein, but other such layered silicates, suchas those having the general formula NaMSi_(x) O_(2x+1).yH₂ O wherein Mis sodium or hydrogen, x is a number from 1.9 to 4, preferably 2, and yis a number from 0 to 20, preferably 0 can be used herein. Various otherlayered silicates from Hoechst include NaSKS-5, NaSKS-7 and NaSKS-11, asthe alpha, beta and gamma forms. As noted above, the delta-Na₂ SiO₅(NaSKS-6 form) is most preferred for use herein. Other silicates mayalso be useful such as for example magnesium silicate, which can serveas a crispening agent in granular formulations, as a stabilizing agentfor oxygen bleaches, and as a component of suds control systems.

Aluminosilicate builders are usefuil in the present invention.Aluminosilicate builders are of great importance in most currentlymarketed heavy duty granular detergent compositions. Aluminosilicatebuilders include those having the empirical formula:

    M.sub.z (zAlO.sub.2).sub.y ].xH.sub.2 O

wherein z and y are integers of at least 6, the molar ratio of z to y isin the range from 1.0 to about 0.5, and x is an integer from about 15 toabout 264.

Useful aluminosilicate ion exchange materials are commerciallyavailable. These aluminosilicates can be crystalline or amorphous instructure and can be naturally-occurring aluminosilicates orsynthetically derived. A method for producing aluminosilicate ionexchange materials is disclosed in U.S. Pat. No. 3,985,669, Krummel, etal, issued Oct. 12, 1976. Preferred synthetic crystallinealuminosilicate ion exchange materials useful herein are available underthe designations Zeolite A, Zeolite P (B), Zeolite MAP and Zeolite X. Inan especially preferred embodiment, the crystalline aluminosilicate ionexchange material has the formula:

    Na.sub.12 [(AlO.sub.2).sub.12 (SiO.sub.2).sub.12 ].xH.sub.2 O

wherein x is from about 20 to about 30, especially about 27. Thismaterial is known as Zeolite A. Dehydrated zeolites (x=0-10) may also beused herein. Preferably, the aluminosilicate has a particle size ofabout 0.1-10 microns in diameter.

Organic detergent builders suitable for the purposes of the presentinvention include, but are not restricted to, a wide variety ofpolycarboxylate compounds. As used herein, "polycarboxylate" refers tocompounds having a plurality of carboxylate groups, preferably at least3 carboxylates. Polycarboxylate builder can generally be added to thecomposition in acid form, but can also be added in the form of aneutralized salt. When utilised in salt form, alkali metals, such assodium, potassium, and lithium, or alkanolammonium salts are preferred.

Included among the polycarboxylate builders are a variety of categoriesof useful materials. One important category of polycarboxylate buildersencompasses the ether polycarboxylates, including oxydisuccinate, asdisclosed in Berg, U.S. Pat. No. 3,128,287, issued Apr. 7, 1964, andLamberti et al, U.S. Pat. No. 3,635,830, issued Jan. 18, 1972. See also"TMS/TDS" builders of U.S. Pat. No. 4,663,071, issued to Bush et al, onMay 5, 1987. Suitable ether polycarboxylates also include cycliccompounds, particularly alicyclic compounds, such as those described inU.S. Pat. Nos. 3,923,679; 3,835,163; 4,158,635; 4,120,874 and 4,102,903.

Other useful detergency builders include the etherhydroxypolycarboxylates, copolymers of maleic anhydride with ethylene orvinyl methyl ether, 1,3,5-trihydroxy benzene-2,4,6-trisulphonic acid,and carboxymethyloxysuccinic acid, the various alkali metal, ammoniumand substituted ammonium salts of polyacetic acids such asethylenediamine tetraacetic acid and nitrilotriacetic acid, as well aspolycarboxylates such as mellitic acid, succinic acid, oxydisuccinicacid, polymaleic acid, benzene 1,3,5-tricarboxylic acid,carboxymethyloxysuccinic acid, and soluble salts thereof.

Citrate builders, e.g., citric acid and soluble salts thereof(particularly sodium salt), are polycarboxylate builders of particularimportance. Citrates may be used in granular compositions, especially incombination with zeolite and/or layered silicate builders.Oxydisuccinates are also especially useful in such compositions andcombinations.

Also suitable in the detergent compositions of the present invention arethe 3,3-dicarboxy-4-oxa-1,6-hexanedioates and the related compoundsdisclosed in U.S. Pat. No. 4,566,984, Bush, issued Jan. 28, 1986. Usefulsuccinic acid builders include the C₅ -C₂₀ alkyl and alkenyl succinicacids and salts thereof. A particularly preferred compound of this typeis dodecenylsuccinic acid. Specific examples of succinate buildersinclude: laurylsuccinate, myristylsuccinate, palmitylsuccinate,2-dodecenylsuccinate (preferred), 2-pentadecenylsuccinate, and the like.Laurylsuccinates are the preferred builders of this group, and aredescribed in European Patent Application 86200690.5/0,200,263, publishedNov. 5, 1986.

Other suitable polycarboxylates are disclosed in U.S. Pat. No.4,144,226, Crutchfield et al, issued Mar. 13, 1979 and in U.S. Pat. No.3,308,067, Diehl, issued Mar. 7, 1967. See also Diehl U.S. Pat.3,723,322.

Fatty acids, e.g., C₁₂ -C₁₈ monocarboxylic acids, can also beincorporated into the compositions alone, or in combination with theaforesaid builders, especially citrate and/or the succinate builders, toprovide additional builder activity. Such use of fatty acids willgenerally result in a diminution of sudsing, which should be taken intoaccount by the formulator.

In situations where phosphorus-based builders can be used, the variousalkali metal phosphates such as the well-known sodium tripolyphosphates,sodium pyrophosphate and sodium orthophosphate can be used. Phosphonatebuilders such as ethane-1-hydroxy-1,1-diphosphonate and other knownphosphonates (see, for example, U.S. Pat. Nos. 3,159,581; 3,213,030;3,422,021; 3,400,148 and 3,422,137) can also be used.

The tabletted detergent composition of the present invention preferablycomprises builders selected from sulphates, phosphates, silicates andmixtures thereof. More preferably the builders are selected in order ofpreference from silicate, sulphate, citrate, and mixtures thereof.

Water

According to the present invention the tabletted detergent compositionsalso comprise as an essential ingredient from 5% to 30%, preferably from5% to 20%, most preferably from 10% to 15% of water. The water contentof the tabletted detergent composition of the present invention may bedetermined by methods known and described in the art, such asdistillation methods. Such methods determine the total water contenti.e. mobile/free water and bound water present in the tablet.

Whilst not wishing to be bound by theory, it is believed that the ratioof free and bound water present in the tablet contributes to thehardness of the tablet. This ratio of free and bound water may bemeasured in terms of percentage equilibrium relative humidity ordetection water. Preferably, the percentage equilibrium relativehumidity is from 29% to 50%, preferably from 30% to 40%, more preferablyfrom 30% to 38%, most preferably from 30% to 35% at 26° C. The waterpresent in the tablet is mainly derived from the tablet ingredientsthemselves such as from the builder system. However, it has been foundthat in order to achieve the optimal ratio of free/mobile and boundwater, water must be added by the formulator. Thus, it is an essentialfeature of the present invention that additional water is added to thedetergent formulation, preferably prior to compression. Alternatively,the additional water is added to the detergent composition prior totabletting by exposing the composition to a controlled humidenvironment. Preferably the tabletted detergent composition comprisesfrom 0.3% to 4%, more preferably from 0.3% to 3%, most preferably from0.3% to 1% of water by weight of the total detergent composition isadded by the formulator and is not derived from the components of thetabletted composition. According to the present invention the ratio oftotal water content of the tabletted composition to added water is inthe ratio of from 100:1 to 5:4, preferably 70:1 to 5:3, more preferablyfrom 50:1 to 15:1.

Adjunct Ingredients

The compositions herein can optionally include one or more otherdetergent adjunct materials or other materials for assisting orenhancing cleaning performance, treatment of the substrate to becleaned, or to modify the aesthetics of the detergent composition (e.g.,perfumes, colorants, dyes, etc.). The following are illustrativeexamples of such adjunct materials.

Detersive Surfactants

Nonlimiting examples of surfactants useful herein typically at levelsfrom about 1% to about 55%, by weight, include the conventional C₁₁ -C₁₈alkyl benzene sulfonates ("LAS") and primary, branched-chain and randomC₁₀ -C₂₀ alkyl sulphates ("AS"), the C₁₀ -C₁₈ secondary (2,3) alkylsulphates of the formula CH₃ (CH₂)_(x) (CHOSO₃ ⁻ M⁺)CH₃ and CH₃(CH₂)_(y) (CHOSO₃ ⁻ M⁺) CH₂ CH₃ where x and (y+1) are integers of atleast about 7, preferably at least about 9, and M is awater-solubilizing cation, especially sodium, unsaturated sulphates suchas oleoyl sulphate, the C_(10-C) ₁₈ alkyl alkoxy sulphates ("AE_(x) S";especially EO 1-7 ethoxy sulphates), C₁₀ -C₁₈ alkyl alkoxy carboxylates(especially the EO 1-5 ethoxycarboxylates), the C₁₀₋₁₈ glycerol ethers,the C₁₀ -C₁₈ alkyl polyglycosides and their corresponding sulphatedpolyglycosides, and C₁₂ -C₁₈ alpha- fatty acid esters. If desired, theconventional nonionic and amphoteric surfactants such as the C₁₂ -C₁₈alkyl ethoxylates ("AE") including the so-called narrow peaked alkylethoxylates and C₆ -C₁₂ alkyl phenol alkoxylates (especially ethoxylatesand mixed ethoxy/propoxy), C₁₂ -C₁₈ betaines and sulfobetaines("sultaines"), C₁₀ -C₁₈ amine oxides, and the like, can also be includedin the overall compositions. The C₁₀ -C₁₈ N-alkyl polyhydroxy fatty acidamides can also be used. Typical examples include the C₁₂ -C₁₈N-methylglucamides. See WO 9,206,154. Other sugar-derived surfactantsinclude the N-alkoxy polyhydroxy fatty acid amides, such as C₁₀ -C₁₈N-(3-methoxypropyl) glucamide. The N-propyl through N-hexyl C₁₂ -C₁₈glucamides can be used for low sudsing. C₁₀ -C₂₀ conventional soaps mayalso be used. Mixtures of anionic and nonionic surfactants areespecially useful. Other conventional useful surfactants are listed instandard texts.

Polymeric Dispersing Agents

Polymeric dispersing agents can advantageously be utilised at levelsfrom about 0.1% to about 7%, by weight, in the compositions herein,especially in the presence of zeolite and/or layered silicate builders.Suitable polymeric dispersing agents include polyethylene glycols PEG,although others known in the art can also be used. It is believed,though it is not intended to be limited by theory, that polymericdispersing agents enhance overall detergent builder performance, whenused in combination with other builders (including lower molecularweight polycarboxylates) by crystal growth inhibition, particulate soilrelease peptization, and anti-redeposition.

PEG can exhibit dispersing agent performance as well as act as a claysoil removal-antiredeposition agent. Typical molecular weight ranges forthese purposes range from about 500 to about 100,000; preferably fromabout 1,000 to about 50,000, more preferably from about 1,500 to about10,000.

Polyaspartate and polyglutamate dispersing agents may also be used,especially in conjunction with zeolite builders. Dispersing agents suchas polyaspartate preferably have a molecular weight (avg.) of about10,000.

Polymeric Carboxylates

According to the present invention another essential component of thetabletted detergent composition is a polymeric polycarboxylate. Saidpolymeric polycarboxylate is present at from 1% to 30%, preferably from1% to 10%, more preferably from 1% to 5%.

Polymeric polycarboxylate materials can be prepared by polymerizing orcopolymerizing suitable unsaturated monomers, preferably in their acidform. Unsaturated monomeric acids that can be polymerized to formsuitable polymeric polycarboxylates include acrylic acid, maleic acid(or maleic anhydride), fumaric acid, itaconic acid, aconitic acid,mesaconic acid, citraconic acid and methylenemalonic acid. The presencein the polymeric polycarboxylates herein or monomeric segments,contaning no carboxylate radicals such as vinylmethyl ether, styrene,ethylene, etc. is suitable provided that such segments do not constitutemore than about 40% by weight.

Particularly suitable polymeric polycarboxylates can be derived fromacrylic acid. Such acrylic acid-based polymers which are useful hereinare the water-soluble salts of polymerized acrylic acid. The averagemolecular weight of such polymers in the acid form preferably rangesfrom about 2,000 to 10,000, more preferably from about 4,000 to 7,000and most preferably from about 4,000 to 5,000. Water-soluble salts ofsuch acrylic acid polymers can include, for example, the alkali metal,ammonium and substituted ammonium salts. Soluble polymers of this typeare known materials. Use of polyacrylates of this type in detergentcompositions has been disclosed, for example, in Diehl, U.S. Pat. No.3,308,067, issued Mar. 7, 1967.

Acrylic/maleic-based copolymers may also be used as a preferredcomponent of the dispersing/anti-redeposition agent. Such materialsinclude the water-soluble salts of copolymers of acrylic acid and maleicacid. The average molecular weight of such copolymers in the acid formpreferably ranges from about 2,000 to 100,000, more preferably fromabout 5,000 to 75,000, most preferably from about 7,000 to 65,000. Theratio of acrylate to maleate segments in such copolymers will generallyrange from about 30:1 to about 1:1, more preferably from about 10:1 to2:1. Water-soluble salts of such acrylic acid/maleic acid copolymers caninclude, for example, the alkali metal, ammonium and substitutedammonium salts. Soluble acrylate/maleate copolymers of this type areknown materials which are described in European Patent Application No.66915, published Dec. 15, 1982, as well as in EP 193,360, published Sep.3, 1986, which also describes such polymers comprisinghydroxypropylacrylate. Still other useful dispersing agents include themaleic/acrylic/vinyl alcohol terpolymers. Such materials are alsodisclosed in EP 193,360, including, for example, the 45/45/10 terpolymerof acrylic/maleic/vinyl alcohol.

Chelating Agents

The detergent compositions herein may also optionally contain one ormore iron and/or manganese chelating agents. Such chelating agents canbe selected from the group consisting of amino carboxylates, aminophosphonates, polyfunctionally-substituted aromatic chelating agents andmixtures therein, all as hereinafter defined. Without intending to bebound by theory, it is believed that the benefit of these materials isdue in part to their exceptional ability to remove iron and manganeseions from washing solutions by formation of soluble chelates.

Amino carboxylates useful as optional chelating agents includeethylenediaminetetracetates, N-hydroxyethylethylene diaminetriacetates,nitrilotriacetates, ethylenediamine tetraproprionates,triethylenetetraamine-hexacetates, diethylenetriaminepentaacetates, andethanoldiglycines, alkali metal, ammonium, and substituted ammoniumsalts therein and mixtures therein.

Amino phosphonates are also suitable for use as chelating agents in thecompositions of the invention when at least low levels of totalphosphorus are permitted in detergent compositions, and includeethylenediaminetetrakis (methylenephosphonates) as DEQUEST. Preferred,these amino phosphonates to not contain alkyl or alkenyl groups withmore than about 6 carbon atoms.

Polyfunctionally-substituted aromatic chelating agents are also usefulin the compositions herein. See U.S. Pat. No. 3,812,044, issued May 21,1974, to Connor et al. Preferred compounds of this type in acid form aredihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.

A preferred biodegradable chelator for use herein is ethylenediaminedisuccinate ("EDDS"), especially the [S,S] isomer as described in U.S.Pat. No. 4,704,233, Nov. 3, 1987, to Hartman and Perkins.

If utlaised, these chelating agents will generally comprise from about0.1% to about 10% by weight of the detergent compositions herein. Morepreferably, if utilised, the chelating agents will comprise from about0.1% to about 3.0% by w eight of such compositions.

Enzymes

Enzymes can be included in the formulations herein for a wide variety offabric laundering purposes, including removal of protein-based,carbohydrate-based, or triglyceride-based stains. The enzymes to beincorporated include proteases, amylases, lipases, cellulases, and.peroxidases, as well as mixtures thereof. Other types of enzymes mayalso be included. They may be of any suitable origin, such as vegetable,animal, bacterial, fungal and yeast origin. However, their choice isgoverned by several factors such as pH-activity and/or stability optima,thermostability, stability versus active detergents, builders and so on.In this respect bacterial or fungal enzymes are preferred, such asbacterial amylases and proteases, and tungal cellulases.

Enzyme s are normally incorporated at levels sufficient to provide up toabout 5 mg by weight, more typically about 0.01 mg to about 3 mg, ofactive enzyme per gram of the composition. Stated otherwise, thecompositions herein will typically comprise from about 0.001% to about10%, preferably 0.01% to 5% by weight of a commercial enzymepreparation. Protease enzymes are usually present in such commercialpreparations at levels sufficient to provide from 0.005 to 0.1 Ansonunits (AU) of activity per gram of composition.

Suitable examples of proteases are the subtilisins which are obtainedfrom particular strains of B. subtilis and B. licheniforms. Anothersuitable protease is obtained from a strain of Bacillus, having maximumactivity throughout the pH range of 8-12, developed and sold by NovoIndustries A/S under the registered trade name ESPERASE. The preparationof this enzyme and analogous enzymes is described in British PatentSpecification No. 1,243,784 of Novo. Proteolytic enzymes suitable forremoving protein-based stains that are commercially available includethose sold under the tradenames ALCALASE and SAVINASE by Novo IndustriesA/S (Denmark) and MAXATASE by International Bio-Synthetics, Inc. (TheNetherlands). Other proteases include Protease A (see European PatentApplication 130,756, published Jan. 9, 1985) and Protease B (seeEuropean Patent Application Ser. No. 87303761.8, filed Apr. 28, 1987,and European Patent Application 130,756, Bott et al, published Jan. 9,1985).

Amylases include, for example, Δ-amylases described in British PatentSpecification No. 1,296,839 (Novo), RAPIDASE, InternationalBio-Synthetics, Inc. and TERMAMYL, Novo Industries.

The cellulase usable in the present invention include both bacterial orfungal cellulase. Preferably, they will have a pH optimum of between 5and 9.5. Suitable cellulases are disclosed in U.S. Pat. No. 4,435,307,Barbesgoard et al, issued Mar. 6, 1984, which discloses fungal cellulaseproduced from Humicola insolens and Humicola strain DSM1800 or acellulase 212-producing fungus belonging to the genus Aeromonas, andcellulase extracted from the hepatopancreas of a marine mollusk(Dolabella Auricula Solander). Suitable cellulases are also disclosed inGB-A-2.075.028; GB-A-2.095.275 and DE-OS-2.247.832. CAREZYME (Novo) isespecially useful.

Suitable lipase enzymes for detergent usage include those produced bymicroorganisms of the Pseudomonas group, such as Pseudomonas stutzeriATCC 19.154, as disclosed in British Patent 1,372,034. See also lipasesin Japanese Patent Application 53,20487, laid open to public inspectionon Feb. 24, 1978. This lipase is available from Amano Pharmaceutical Co.Ltd., Nagoya, Japan, under the trade name Lipase P "Amano," hereinafterreferred to as "Amano-P." Other commercial lipases include Amano-CES,lipases ex Chromobacter viscosum, e.g. Chromobacter viscosum var.lipolyticum NRRLB 3673, commercially available from Toyo Jozo Co.,Tagata, Japan; and further Chromobacter viscosum lipases from U.S.Biochemical Corp., U.S.A. and Disoynth Co., The Netherlands, and lipasesex Pseudomonas gladioli. The LIPOLASE enzyme derived from Humicolalanuginosa and commercially available from Novo (see also EPO 341,947)is a preferred lipase for use herein.

Peroxidase enzymes are used in combination with oxygen sources, e.g.,percarbonate, perborate, persulfate, hydrogen peroxide, etc. They areused for "solution bleaching," i.e. to prevent transfer of dyes orpigments removed from substrates during wash operations to othersubstrates in the wash solution. Peroxidase enzymes are known in theart, and include, for example, horseradish peroxidase, ligninase, andhaloperoxidase such as chloro- and bromo-peroxidase.Peroxidase-containing detergent compositions are disclosed, for example,in PCT International Application WO 89/099813, published Oct. 19, 1989,by O. Kirk, assigned to Novo Industries A/S.

A wide range of enzyme materials and means for their incorporation intosynthetic detergent compositions are also disclosed in U.S. Pat. No.3,553,139, issued Jan. 5, 1971 to McCarty et al. Enzymes are furtherdisclosed in U.S. Pat. No. 4,101,457, Place et al, issued Jul. 18, 1978,and in U.S. Pat. No. 4,507,219, Hughes, issued Mar. 26, 1985, both.Enzyme materials useful for liquid detergent formulations, and theirincorporation into such formulations, are disclosed in U.S. Pat. No.4,261,868, Hora et al, issued Apr. 14, 1981. Enzymes for use indetergents can be stabilized by various techniques. Enzyme stabilizationtechniques are disclosed and exemplified in U.S. Pat. No. 3,600,319,issued Aug. 17, 1971 to Gedge, et al, and European Patent ApplicationPublication No. 0 199 405, Application No. 86200586.5, published Oct.29, 1986, Venegas. Enzyme stabilization systems are also described, forexample, in U.S. Pat. 3,519,570.

Enzyme Stabilizers

The enzymes employed herein are stabilized by the presence ofwater-soluble sources of calcium and/or magnesium ions in the finishedcompositions which provide such ions to the enzymes. (Calcium ions aregenerally somewhat more effective than magnesium ions and are preferredherein if only one type of cation is being used.) Additional stabilitycan be provided by the presence of various other art-disclosedstabilizers, especially borate species: see Severson, U.S. 4,537,706.

Bleaching Compounds--Bleaching Agents and Bleach Activators

The detergent compositions herein may optionally contain bleachingagents or bleaching compositions containing a bleaching agent and one ormore bleach activators. When present, bleaching agents will typically beat levels of from about 0.1% to about 30%, more typically from about 1%to about 20%, of the detergent composition, especially for fabriclaundering. If present, the amount of bleach activators will typicallybe from about 0.1% to about 60%, more typically from about 0.5% to about40% of the bleaching composition comprising the bleachingagent-plus-bleach activator.

The bleaching agents used herein can be any of the bleaching agentsuseful for detergent compositions in textile cleaning, hard surfacecleaning, or other cleaning purposes that are now known or become known.These include oxygen bleaches as well as other bleaching agents.Perborate bleaches, e.g., sodium perborate (e.g., mono- ortetra-hydrate) can be used herein.

Another category of bleaching agent that can be used without restrictionencompasses percarboxylic acid bleaching agents and salts thereof.Suitable examples of this class of agents include magnesiummonoperoxyphthalate hexahydrate, the magnesium salt of metachloroperbenzoic acid, 4-nonylamino-4-oxoperoxybutyric acid anddiperoxydodecanedioic acid. Such bleaching agents are disclosed in U.S.Pat. No. 4,483,781, Hartman, issued Nov. 20, 1984, U.S. patentapplication Ser. No. 740,446, Burns et al, filed Jun. 3, 1985, EuropeanPatent Application 0,133,354, Banks et al, published Feb. 20, 1985, andU.S. Pat. No. 4,412,934, Chung et al, issued Nov. 1, 1983. Highlypreferred bleaching agents also include 6-nonylamino-6-oxoperoxycaproicacid as described in U.S. Pat. No. 4,634,551, issued Jan. 6, 1987 toBurns et al.

Peroxygen bleaching agents can also be used. Suitable peroxygenbleaching compounds include sodium carbonate peroxyhydrate andequivalent "percarbonate" bleaches, sodium pyrophosphate peroxyhydrate,urea peroxyhydrate, and sodium peroxide. Persulfate bleach (e.g., OXONE,manufactured commercially by DuPont) can also be used.

Mixtures of bleaching agents can also be used. Peroxygen bleachingagents, the perborates, etc., are preferably combined with bleachactivators, which lead to the in situ production in aqueous solution(i.e., during the washing process) of the peroxy acid corresponding tothe bleach activator. Various nonlimiting examples of activators aredisclosed in U.S. Pat. No. 4,915,854, issued Apr. 10, 1990 to Mao et al,and U.S. Pat. No. 4,412,934. The nonanoyloxybenzene sulfonate (NOBS) andtetraacetyl ethylene diamine (TAED) activators are typical, and mixturesthereof can also be used. See also U.S. Pat. No. 4,634,551 for othertypical bleaches and activators useful herein.

Highly preferred amido-derived bleach activators are those of theformulae:

    R.sup.1 N(R.sup.5)C(O)R.sup.2 C(O)L or R.sup.1 C(O)N(R.sup.5)R.sup.2 C(O)L

wherein R¹ is an alkyl group containing from about 6 to about 12 carbonatoms, R² is an alkylene containing from 1 to about 6 carbon atoms, R⁵is H or alkyl, aryl, or alkaryl containing from about 1 to about 10carbon atoms, and L is any suitable leaving group. A leaving group isany group that is displaced from the bleach activator as a consequenceof the nucleophilic attack on the bleach activator by the perhydrolysisanion. A preferred leaving group is phenyl sulfonate.

Preferred examples of bleach activators of the above formulae include(6-octanamido-caproyl)oxybenzenesulfonate,(6-nonanamido-caproyl)oxybenzenesulfonate,(6-decanamido-caproyl)oxybenzenesulfonate, and mixtures thereof asdescribed in U.S. Pat. No. 4,634,551, incorporated herein by reference.

Another class of bleach activators comprises the benzoxazin-typeactivators disclosed by Hodge et al in U.S. Pat. No. 4,966,723, issuedOct. 30, 1990, incorporated herein by reference. A highly preferredactivator of the benzoxazin-type is: ##STR1##

Still another class of preferred bleach activators includes the acyllactam activators, especially acyl caprolactams and acyl valerolactamsof the formulae: ##STR2##

wherein R⁶ is H or an alkyl, aryl, alkoxyaryl, or alkaryl groupcontaining from 1 to about 12 carbon atoms. Highly preferred lactamactivators include benzoyl caprolactam, octanoyl caprolactam,3,5,5-trimethylhexanoyl caprolactam, nonanoyl caprolactam, decanoylcaprolactam, undecenoyl caprolactam, benzoyl valerolactam, octanoylvalerolactam, decanoyl valerolactam, undecenoyl valerolactam, nonanoylvalerolactam, 3,5,5-trimethylhexanoyl valerolactam and mixtures thereof.See also U.S. Pat. No. 4,545,784, issued to Sanderson, Oct. 8, 1985,incorporated herein by reference, which discloses acyl caprolactams,including benzoyl caprolactam, adsorbed into sodium perborate.

Bleaching agents other than oxygen bleaching agents are also known inthe art and can be utilised herein. One type of non-oxygen bleachingagent of particular interest includes photoactivated bleaching agentssuch as the sulfonated zinc and/or aluminium phthalocyanines. See U.S.Pat. No. 4,033,718, issued Jul. 5, 1977 to Holcombe et al. If used,detergent compositions will typically contain from about 0.025% to about1.25%, by weight, of such bleaches, especially sulfonate zincphthalocyanine.

If desired, the bleaching compounds can be catalyzed by means of amanganese compound. Such compounds are well known in the art andinclude, for example, the manganese-based catalysts disclosed in U.S.Pat. No. 5,246,621, U.S. Pat. No. 5,244,594; U.S. Pat. No. 5,194,416;U.S. Pat. No. 5,114,606; and European Pat. App. Pub. Nos. 549,271A1,549,272A1, 544,440A2, and 544,490A1; Preferred examples of thesecatalysts include Mn^(IV) ₂ (u-O)₃(1,4,7-trimethyl-1,4,7-triazacyclo-nonane)₂ (PF₆)₂, Mn^(III) ₂ (u-O)₁(u-OAc)₂ (1,4,7-trimethyl-1,4,7-triazacyclononane)₂₋ (ClO₄)₂, Mn^(IV) ₄(u-O)₆ (1,4,7-triazacyclononane)₄ (ClO₄)₄, Mn^(III) Mn^(IV) ₄ (u-O)₁(u-OAc)₂₋ (1,4,7-trimethyl-1,4,7-triazacyclononane)₂ (ClO₄)₃, Mn^(IV)(1,4,7-trimethyl-1,4,7-triazacyclononane)-(OCH₃)₃ (PF₆), and mixturesthereof. Other metal-based bleach catalysts include those disclosed inU.S. Pat. No. 4,430,243 and U.S. Pat. No. 5,114,611. The use ofmanganese with various complex ligands to enhance bleaching is alsoreported in the following U.S. Pat. Nos.: 4,728,455; 5,284,944;5,246,612; 5,256,779; 5,280,117; 5,274,147; 5,153,161; 5,227,084;

Corrosion Inhibitor Compound

The compositions may contain corrosion inhibitors preferably selectedfrom organic silver coating agents, particularly paraffin,nitrogen-containing corrosion inhibitor compounds, bismuth compounds andMn(II) compounds, particularly Mn(II) salts of organic ligands.

Organic silver coating agents are described in PCT Publication No.WO94/16047 (attorney's docket no. CM497M) and copending UK ApplicationNo. UK 9413729.6 (attorney's docket no. CM750F). Nitrogen-containingcorrosion inhibitor compounds are disclosed in copending EuropeanApplication no. EP 93202095.1 (attorney's docket no. CM571F). Mn(II)compounds for use in corrosion inhibition are described in copending UKApplication No. 9418567.5 (attorney's docket no. CM719FM).

Organic Silver Coating Agents

Organic silver coating agent may be incorporated at a level of from0.05% to 10%, preferably from 0.1% to 5% by weight of the totalcomposition.

The functional role of the silver coating agent is to form `in use` aprotective coating layer on any silverware components of the washload towhich the compositions of the invention are being applied. The silvercoating agent should hence have a high affinity for attachment to solidsilver surfaces, particularly when present in as a component of anaqueous washing and bleaching solution with which the solid silversurfaces are being treated.

Suitable organic silver coating agents herein include fatty esters ofmono- or polyhydric alcohols having from 1 to about 40 carbon atoms inthe hydrocarbon chain.

The fatty acid portion of the fatty ester can be obtained from mono- orpoly-carboxylic acids having from 1 to about 40 carbon atoms in thehydrocarbon chain. Suitable examples of monocarboxylic fatty acidsinclude behenic acid, stearic acid, oleic acid, palmitic acid, myristicacid, lauric acid, acetic acid, propionic acid, butyric acid, isobutyricacid, valeric acid, lactic acid, glycolic acid andβ,β'-dihydroxyisobutyric acid. Examples of suitable polycarboxylic acidsinclude: n-butyl-malonic acid, isocitric acid, citric acid, maleic acid,malic acid and succinic acid.

The fatty alcohol radical in the fatty ester can be represented by mono-or polyhydric alcohols having from 1 to 40 carbon atoms in thehydrocarbon chain. Examples of suitable fatty alcohols include; behenyl,arachidyl, cocoyl, oleoyl and lauryl alcohol, ethylene glycol, glycerol,ethanol, isopropanol, vinyl alcohol, diglycerol, xylitol, sucrose,erythritol, pentaerythritol, sorbitol or sorbitan.

Preferably, the fatty acid and/or fatty alcohol group of the fatty esteradjunct material have from 1 to 24 carbon atoms in the alkyl chain.

Preferred fatty esters herein are ethylene glycol, glycerol and sorbitanesters wherein the fatty acid portion of the ester normally comprises aspecies selected from behenic acid, stearic acid, oleic acid, palmiticacid or myristic acid.

The glycerol esters are also highly preferred. These are the mono-, di-or trimesters of glycerol and the fatty acids as defined above.

Specific examples of fatty alcohol esters for use herein include:stearyl acetate, palmityl di-lactate, cocoyl isobutyrate, oleyl maleate,oleoyl dimaleate, and tallowyl proprionate. Fatty acid esters usefulherein include: xylitol monopalmitate, pentaerythritol monostearate,sucrose monostearate, glycerol monostearate, ethylene glycolmonostearate, sorbitan esters. Suitable sorbitan esters include sorbitanmonostearate, sorbitan palmitate, sorbitan monolaurate, sorbitanmonomyristate, sorbitan monobehenate, sorbitan mono-oleate, sorbitandilaurate, sorbitan distearate, sorbitan dibehenate, sorbitan dioleate,and also mixed tallowalkyl sorbitan mono- and di-esters.

Glycerol monostearate, glycerol mono-oleate, glycerol monopalmitate,glycerol monobehenate, and glycerol distearate are preferred glycerolesters herein.

Suitable organic silver coating agents include triglycerides, mono ordiglycerides, and wholly or partially hydrogenated derivatives thereof,and any mixtures thereof. Suitable sources of fatty acid esters includevegetable and fish oils and animal fats. Suitable vegetable oils includesoy bean oil, cotton seed oil, castor oil, olive oil, peanut oil,safflower oil, sunflower oil, rapeseed oil, grapeseed oil, palm oil andcorn oil.

Waxes, including microcrystalline waxes are suitable organic silvercoating agents herein. Preferred waxes have a melting point in the rangefrom about 35° C. to about 110° C. and comprise generally from 12 to 70carbon atoms. Preferred are petroleum waxes of the paraffin andmicrocrystalline type which are composed of long-chain saturatedhydrocarbon compounds.

Alginates and gelatin are suitable organic silver coating agents herein.

Dialkyl amine oxides such as C₁₂ -C₂₀ methylamine oxide, and dialkylquaternary ammonium compounds and salts, such as the C₁₂ -C₂₀methylammonium halides are also suitable.

Other suitable organic silver coating agents include certain polymericmaterials. Polyvinylpyrrolidones with an average molecular weight offrom 12,000 to 700,000, polyethylene glycols (PEG) with an averagemolecular weight of from 600 to 10,000, polyamine N-oxide polymers,copolymers of N-vinylpyrrolidone and N-vinylimidazole, and cellulosederivatives such as methylcellulose, carboxymethylcellulose andhydroxyethylcellulose are examples of such polymeric materials.

Certain perfume materials, particularly those demonstrating a highsubstantivity for metallic surfaces, are also useful as the organicsilver coating agents herein.

Other Ingredients

A wide variety of other ingredients useful in detergent compositions canbe included in the compositions herein, including other activeingredients, carriers, hydrotropes, processing aids, dyes or pigments,etc. If desired, soluble magnesium salts such as MgCl₂, MgSO₄, and thelike, can be added at levels of, typically, 0.1%-2%, to provide enhancedgrease removal performance. Ingredients may also be incorporated toassist in the tabletting process such as lubricating agents, sodiumacetate and nonionic surfactants.

Tablet Preparation

Another aspect of the present invention relates to the preparation ofthe tabletted detergent composition. The tablet may be manufacturedusing any suitable compacting process, such as tabletting, briquettingor extrusion, preferably tabletting. Preferably the tablets aremanufactured using a standard rotary tabletting press (such as CourtoyRS) using compression forces of from 5 to 13KN/cm², more preferably from5 to 11KN/cm².

According to the present invention the tablets are prepared by drymixing the not fully hydrated builder/filler system, optionalingredients selected from polymeric polycarboxylates, chelants, bleachand bleach activator and then adding water and optionally otheringredients which may be sprayed on such as nonionic surfactants,chelants and silvercare additives. Prior to compaction any additionalsensitive ingredients such as enzymes, dyes and perfumes are dry mixed.

The composition is then tabletted by conventional means, on a 12 headrotary press under a compression force of 5-13KN/cm² so that the tablethas a minimum hardness of 176N to 245N, preferably from 195N to 275N,measured by a C100 hardness test as supplied by I. Holland Instruments.These processes may be used to prepare homogenous or layered tablets ofany size or shape. Preferably the tablets are symmetrical to ensure theuniform dissolution of the tablet in the wash liquor.

According to the present invention said tabletted detergent compositionmay find utility in all types of automatic dish- and laundry washingmachines including industrial and domestic.

Abbreviations used in Examples

In the detergent compositions, the abbreviated component identificationshave the following meanings:

    ______________________________________                                        35EY       A mixture of C.sub.13-15 predominantly linear                                 primary alcohol condensed with an average of                                  2 and 6 moles of ethylene oxide                                    Silicate   Sodium Silicate (SiO.sub.2 :Na.sub.2 O ratio = 2.0)                Sulphate   Anhydrous sodium sulphate                                          AA         Homopolymer of acrylic acid, average                                          molecular weight about 8,000.                                      Citrate    Tri-sodium citrate dihydrate                                       DETPMP     Diethylene triamine penta (Methylene                                          phosphonic acid), marketed by Monsanto under                                  the Tradename Dequest 2060                                         TAED       Tetraacetyl ethylene diamine                                       Perborate  Anhydrous sodium perborate monohydrate                                        bleach                                                             Paraffin   Paraffin oil sold under the tradename Winog 70                                by Wintershall                                                     ______________________________________                                    

EXAMPLE

The following tabletted detergent compositions suitable for use in anautomatic dishwashing machine were prepared as described. The tabletwere prepared by dry mixing all of the components except HEDP,Benzotrioazole, paraffin, enzymes and the added water. The HEDP,benzotriazole, paraffin, nonionic surfactant and water are then sprayedon and the composition mixed. The enzymes and additional sensitiveingredients are then added prior to compression to produce a 25 gtablet.

    ______________________________________                                        Tablet       Ref     I         II    III                                      ______________________________________                                        Citrate      25      25        33    26.4                                     AA           3.2     3.2       4     3.2                                      Silicate     26.4    26.4      33    26.4                                     HEDP         0.66    0.66      0.83  0.66                                     PB1          1.56    1.56      1.95  1.56                                     PB4          6.92    6.92      8.65  6.91                                     TAED         4.36    4.36      5.45  4.36                                     Enzymes      3       3         3.8   3                                        Silvercare   0.64    0.64      0.8   0.6                                      additive                                                                      35EY         1.2     1.2       1.5   1.2                                      Sulphate     23      22        --    1.95                                     Added Water  0       0.5       0.7   1.0                                      Misc.            Balance to 100%                                              Total water  11.8    12.3      12.5  12.8                                     content                                                                       Equilibrium  28.6    28.8      31.4  30.9                                     relative humidity                                                             at 26° C.                                                              av. Hardness 144N    239N      221N  220N                                     ______________________________________                                    

What is claimed is:
 1. A carbonate free tabletted detergent composition,comprising:from 45% to 80% by weight of a hydratable builder system,said builder system not being fully hydrated; from 12.3% to 15% byweight total water content, said total water content comprising waterderived from said builder system and from added water, wherein theweight ratio of said total water content to added water is in a range offrom 50:1 to 12.8:1; and detergent adjuncts selected from the groupconsisting of surfactants, bleaches, chelants, enzymes, and mixturesthereof.
 2. A tabletted detergent composition according to claim 1,wherein the weight ratio of said water content to added water is in arange of from 24.6:1 to 12.8:1.
 3. A tabletted detergent compositionaccording to claim 1, wherein said tabletted detergent composition has apercentage equilibrium relative humidity in a range of from 29% to 50%at a temperature of 26° C.
 4. A tabletted detergent compositionaccording to claim 1, wherein said builder system is less than 50%hydrated.
 5. A tabletted detergent composition according to claim 1,wherein said builder system comprises builders selected from the groupconsisting of a sulphate, phosphate, citrate, silicate, or a mixturethereof.
 6. A tabletted detergent composition according to claim 5,wherein said builder is a sulphate, citrate, silicate, or mixturethereof.
 7. A tabletted detergent composition according to claim 1,comprising from 65% to 75% by weight of said builder.
 8. A tabletteddetergent composition according to claim 1, further comprising from 1%to 30% by weight of a polymeric polycarboxylate.
 9. A process forproducing tabletted detergent compositions according to claim 1,comprising the steps of:mixing said builder system; adding from 0.3% to4% by weight water; and tabletting the composition by compression.